Horsepower for 69Z 302 w/#140 cam
 

What horsepower can be expected from a newly rebuilt 302 w/140 cam, chambered exh,, original exhaust manifolds, all other engine parts such as intake, heads, carb., are original to the car,

Thanks

Re: Horsepower for 69Z 302 w/#140 cam
 

Mike,

I think it may be a little soggy. Did you build this yet?

Tim

Re: Horsepower for 69Z 302 w/#140 cam
 

My guess would be 350. That cam will move the HP up higher in the band so the manifolds will hamper output.

Re: Horsepower for 69Z 302 w/#140 cam
 

MCR September '87 did exactly this dyno comparison on a freshly rebuilt 30 over 302. It was professionally built, honed with a torque plate, heads milled to achieve 62cc chambers. Did 327hp/6750 with the stock cam, 347hp/6750 with the 140 cam. The 140 cam showed less power up to 6000 rpm. This was a street rebuild for a restoration.

Photos show the engine on the dyno with open headers, no fan or accessories, unrestricted intake. Your results may vary.

June '88 Hot Rod has dyno results from a 302 Traco built for the '68 Penske T/A cars. Shows just over 400hp/6800. Appears to have been tested with a single carb; cross-ram was good for another 40 hp. States an Engle cam was used.

Re: Horsepower for 69Z 302 w/#140 cam
 

I don't know what the horsepower might be, but my brother owned a 70 1/2 Z-28 that was completely stock except for the 140 cam. It had a 4.10 gear, but should have had a 4.56 with that cam. It didn't really come alive until around 4000 rpm. It did have a great sounding idle, even with stock manifolds and factory exhaust.

Re: Horsepower for 69Z 302 w/#140 cam
 

I would think in this day & age you could get a new cam made that would make more power and be more efficient .

Re: Horsepower for 69Z 302 w/#140 cam
 

I think the stock manifolds are the big unknown. There are several popular combinations, but few performance paths w/ the iron exhaust. I would start by talking to Eric about a carb overhaul and I'm sure he would shed some light on what realistic expectations should be. He's run these mills on the dyno w/ all types of exhaust. Keep us updated in this thread on how you make out.

Re: Horsepower for 69Z 302 w/#140 cam
 

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: L78steve</div><div class="ubbcode-body">My guess would be 350. That cam will move the HP up higher in the band so the manifolds will hamper output.</div></div>

I think L78 Steve is pretty close.

Re: Horsepower for 69Z 302 w/#140 cam
 

The new engine is built w/replica #140 cam from Howards Cams, they say it is new technology w/smoother opening &amp; closing ramps than the old GM cam, lash is .022/.022, It has 1 hour of break in time at fast idle from 1200 to 1700 ,, fine tuning the carb. &amp; distributor the 302 is getting very crisp and idles down to 1000 rpm nicely, i need to adjust a couple things but so far it is running great.
I will not dyno the engine, just curious what approximate HP would be.

Re: Horsepower for 69Z 302 w/#140 cam
 

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: miket1</div><div class="ubbcode-body">The new engine is built w/replica #140 cam from Howards Cams, they say it is new technology w/smoother opening &amp; closing ramps than the old GM cam, lash is .022/.022, It has 1 hour of break in time at fast idle from 1200 to 1700 ,, fine tuning the carb. &amp; distributor the 302 is getting very crisp and idles down to 1000 rpm nicely, i need to adjust a couple things but so far it is running great.
I will not dyno the engine, just curious what approximate HP would be.
</div></div>

Do you know how much vacuum your engine makes at idle? Are you running the stock 4053 carb and 480 distributor? I am interested in using this cam in my street dz302 but worried it will have idle issues and load up at idle. I really want to make maximum horsepower using stock parts.

Scott

Re: Horsepower for 69Z 302 w/#140 cam
 

I guess everyone has an opinion on this. I helped a buddy install a 140 cam in his 68 Z in 1970. I also ran a 140 cam in a Z engine with headers for a while in the 80's, so of course, now I am an expert, right? Maybe not. In the 1970 install, we didn't know squat about recurving (and I mean me and my buddy; obviously there were a lot of guys that could do that, but we were oblivious). That 68 didn't idle very well, and didn't run that well until 3600 rpm. With headers and no resonators, it ran like stink after that. Watched him take it to 8,000 rpm repeatedly without a failure. All we did was put one weak advance spring in, leave the other one, and put her back together, then play with timing until it would scream. Stock vac advance can, all hooked up like the factory had it. in my 80's build, the distributor was correctly recurved, but I was unaware of a low vac option for the vac advance, but did know enough to hook it to manifold instead of &quot;ported spark&quot; like the factory did.

Anyway, here is my take based on those experiences, AND some additional facts I have learned since.

1. 1980's build, idling at 1,000 rpm, I never had idle issues using 4053 carb. Power brakes were never starved for vac.
2. Much as I like Mike, and hope this engine is everything he wants, I don't see this being much of an improvement over the 30 30 cam if using manifolds instead of headers.
3. Several knowledgeable guys have insisted the chambered exhaust actually flows WORSE than the stock exhaust. It just makes more noise. I have no hard data to back it up, as I am only an &quot;internet expert&quot; on this. If it is true, then chambered after manifolds just makes things worse. If it can't breath, the cam isn't going to work.
4. Scott asked about 4053 carb and 480 distributor. Both can be used, but the distributor must be recurved and a different vac can (B26) used. Timing all in by 3000, limited to 24 to 26 degrees (at the crank) of centrifugal and about 8 to 10 more vac. Hook vac advance to MANIFOLD vacuum. Start out with initial timing at 8 to 10 <span style="font-weight: bold">without</span> the vac advanced hooked up, again at the crank. With the distributor set up like that you may not even need to re-jet the carb, but then again, you may. You won't know until you get it set up.

Re: Horsepower for 69Z 302 w/#140 cam
 

Another point that will effect the timing is what fuel are you going to use ?

Re: Horsepower for 69Z 302 w/#140 cam
 

Using the original 4053 carb.,rejetted, and the point type dist. w/ a Pertronix module in place of points, 37 degree total timing all in at 3000 rpm.
93 octane gas and 5 gal. of 100 octane aviation gas added to the tank.
Quench on the chambers is .035
Vacuum at 1000 rpm is 5 in.
Not loading up at idle, but I only have 1 hour break in time so far, mostly at fast idle 1200-1700 rpm using Brad Penn break in oil with zinc.
So far it is running good and smoothes out nicely as rpm's come up a little.
I am going to fine tune the dist. a little more this week.
My 69Z is an early build factory chambered exh. car so I don't want to change that, keeping my exh. manifolds and smog equip. on also.
If I don't like the way it performs on the street I will change it back to my .030/.030 cam.

Re: Horsepower for 69Z 302 w/#140 cam
 

I would NOT change it back Mike, I would do what Lynn says about the exhaust and so forth. The 30-30 runs well and if you do not put a steeper gear in it and make that engine breath a little the 140 cam will be a deterrent I believe.
Forget about the smog and all that stuff at this point. Make it run good with a few more changes.

Re: Horsepower for 69Z 302 w/#140 cam
 

Mike: I &quot;get&quot; the vintage build thing, but when you sit down and think about it, I believe it is easier to put on headers, exhaust and gears than to change the cam once it is in the car. I have original exhaust for my car as well as manifolds and smog. I can put them on any time I want to look completely stock.

I am surprised you only have 5 inches of vac at idle. I had a good 10-12 at 1,000 rpm with a 140 cam.

Re: Horsepower for 69Z 302 w/#140 cam
 

I checked the vacuum thru the carb. port, I will check it directly thru the intake to see if its different.

Re: Horsepower for 69Z 302 w/#140 cam
 

Good advice from Lynn. Only thing I noted is that John Hinckley recommends the B28 vacuum can rather than the B26. No idea if there's much (any?) difference though.

Re: Horsepower for 69Z 302 w/#140 cam
 

With vacuum at 5&quot; at idle neither can will pull in that low. You will most likely have to use a ported source to prevent driveability problems at low speeds.
The timing will be all over the place at idle.

Re: Horsepower for 69Z 302 w/#140 cam
 

Don't know the spec of those vac cans. It may be the B28 I was thinking of. I had an MSD on the distributor machine last week with a B26, so that is what made me think of that number. Seems it worked at 8 or 9 inches.

You need the one that will engage with the least vac.

Re: Horsepower for 69Z 302 w/#140 cam
 

I would unhook the vacuum advance from the distributor and run it like that. Had mine done years ago and plugged the hose up. No issues at all.

Re: Horsepower for 69Z 302 w/#140 cam
 

Sam, you are correct, I have had all my vacuum advance distributors plugged since 1970 and run only mechanical advance,they run much better, as I said earlier I need to fine tune this a bit more. If it doesn't dial in correctly I have a new MSD mechanical dist. I will install as they are very easy to dial in.
I have considered going the day 2 route w/ headers, no smog, etc.,really don't want that look, if I lose a few HP. because of restrictive exh. that's ok, I only drive my Z 50 miles a year.
The heat riser looks to be one of the most restrictive parts so I may try removing that.

Re: Horsepower for 69Z 302 w/#140 cam
 

The B26 starts at 4&quot;Hg and is all in at 8. Not sure about the B28 never had one to test. If you running at 5 idle the B26 is too stiff.
I don't know of any can that will work that low.

Re: Horsepower for 69Z 302 w/#140 cam
 

That sounds right on Steve for the B26. I know I remembered 8 for something, and I am betting it was all in by then.

Yeah, Mike, if you aren't going with headers and gears, you will probably do better without VA, as you described.

One other thing, while the 30 30 sounds great at idle, if you are leaving the manifolds and smog on it, and you DO decide to replace the 140, consider a 178 (70 LT-1). Federal Mogul still makes it and it is available cheap from Rock Auto with lifters. I think the lash is 22 24, so you still get some of that good solid lifter sound. But, I would completely understand wanting to go with the 30 30, if for no other reason, just the sound of those lifters at idle, especially with the manifolds, as you can't hear as much exhaust note at idle, even with the chambered exhaust.

Keep us posted.

Re: Horsepower for 69Z 302 w/#140 cam
 

Stock single point distributor works fine. I ran 11.50's (LT-1 motor) in the old days with a Chevy distributor recurved. No issues at 7,500 rpm's.

Re: Horsepower for 69Z 302 w/#140 cam
 

Thanks Lynn, and everyone for the opinions,
Yes the chambered is a little louder, what are the specs on the 178, I wanted to stay away from the .030/.030 because the lifter were too noisy to suit me, I had them set at .026/.026, still noisy, so I decided to try the 140.
one thing I noticed with this 140 cam, my automatic choke works great,,but even at cold startup this cam wants air before the choke is warmed up to open, I am going to adjust the choke so it isn't closed so tight.

Re: Horsepower for 69Z 302 w/#140 cam
 

How does the 140 cam effect lifter noise compared to the 30-30? Just wondering.

Re: Horsepower for 69Z 302 w/#140 cam
 

The 178 has a little less duration. I think the lash is 22 24 so it is a bit quieter than the 30 30. I have a 178 in my 69 L46 motor that is in my car now, and most guys have to ask if it is solid lifter.

I think the 140 recommended lash is 24 24, but can check this evening and say for certain.

I have the specs for the 178 (according to GM) in the Chevy Power book and can post them tonight. Someone probably has them handy.

Re: Horsepower for 69Z 302 w/#140 cam
 

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: L78steve</div><div class="ubbcode-body">The B26 starts at 4&quot;Hg and is all in at 8. Not sure about the B28 never had one to test. If you running at 5 idle the B26 is too stiff.
I don't know of any can that will work that low. </div></div>

Correction, The B28 starts at 4 and is all in at 8. Never had a B26 to test.

Re: Horsepower for 69Z 302 w/#140 cam
 

Thanks Steve.

I have a buddy coming over soon to set up a distributor on my Sun machine. I will get the MSD out and check that vac can to see: 1. which one it is, and 2. when it starts and finishes.

Would be good to have those figures published.

Re: Horsepower for 69Z 302 w/#140 cam
 

Found a great thread over at CRG with advice on the vacuum can for a 480 dist and recurve specs:
http://www.camaros.org/forum/index.php?topic=4045.0;all

Re: Horsepower for 69Z 302 w/#140 cam
 

Cam specs:

140 lash, .024 and .026, duration at lash point: 316 I and 323 E. At .050 lift 243 I 254 E.

178 lash, .024 and .030 (more than I remembered) duration at lash point: .307 I .319 E. At .050 lift, 229 I, 237 E.

Re: Horsepower for 69Z 302 w/#140 cam
 

Send your distributor to MacNeish or Chevy Ray in that OK, Texas area. Then just drop it in.

Re: Horsepower for 69Z 302 w/#140 cam
 

[[email protected]]How does the 140 cam effect lifter noise compared to the 30-30? Just wondering.

The 140 from Howards Cams calls for .022/.022, its not as noisy as the .030/.030, after 1 hour of break in running it sounds pretty nice.

Re: Horsepower for 69Z 302 w/#140 cam
 

Does the 140 cam really perform much better than stock?

Re: Horsepower for 69Z 302 w/#140 cam
 

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: miket1</div><div class="ubbcode-body">[[email protected]]How does the 140 cam effect lifter noise compared to the 30-30? Just wondering.

The 140 from Howards Cams calls for .022/.022, its not as noisy as the .030/.030, after 1 hour of break in running it sounds pretty nice. </div></div>

That &quot;clatter&quot; is music to a gear head! TAZ

Re: Horsepower for 69Z 302 w/#140 cam
 

I would think the best benefit of the 140 cam would be with Headers, 2-1/2&quot; exhaust, a little head work, and a steeper gear. This would help the high rpm breathing. With stock exhaust and manifolds, the engine would be choked right when the cam is starting to make some power.

Paul

Re: Horsepower for 69Z 302 w/#140 cam
 

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: [email protected]</div><div class="ubbcode-body">Does the 140 cam really perform much better than stock? </div></div>

Sam, I have not driven it yet so I dont know, still up on jack stands breaking it in, tuning, etc.
You can hear the solid lifters working but not a loud as the .030/.030 cam .
I had forgotten I had a 6.5 power valve in the carb., installed a 2.5 and it helped smooth out the idle .https://www.yenko.net/ubbthreads/pics..._in_tuning.jpg

Re: Horsepower for 69Z 302 w/#140 cam
 

the 140 cam will probably be at a disadvantage with the smog and cast iron manifolds. car looks good though!

Re: Horsepower for 69Z 302 w/#140 cam
 

Car is looking good Mike. I know it has been a long time coming.

Re: Horsepower for 69Z 302 w/#140 cam
 

Mike,
I see you bought your Z from original owner Dan. Saw this car at our 69 Z/28 display back in 08, was pretty nice then. I see you have the front clip off, are you doing a total resto on this car??